//
//  LJJTabBar.swift
//  Swift--weibo
//
//  Created by 李久健 on 16/8/9.
//  Copyright © 2016年 lijiujian. All rights reserved.
//

import UIKit

//声明协议 需要继承 NSObjectProtocol
protocol LJJTabBarDelegate:NSObjectProtocol{
    //声明方法
    func tabBarButtonClick()
}


class LJJTabBar: UITabBar {

    //声明一个代理
    weak var ljjDelegate:LJJTabBarDelegate?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    //MARK 监听方法
    func buttonClick(){
        ljjDelegate?.tabBarButtonClick()
    }
    //MARK: 设置视图
    private func setupUI(){
        addSubview(composeButton)
    }
    //给子控件设置 frame
    override func layoutSubviews() {
        super.layoutSubviews()
        //子控件的宽度
        let childW = self.frame.width * 0.2
        var index: CGFloat = 0
        
        //遍历子控件
        for value in self.subviews {
            //NSClassFromString 通过字符串转class
            if value.isKindOfClass(NSClassFromString("UITabBarButton")!) {
                //设置 frame
                value.frame.size.width = childW
                value.frame.origin.x = index * childW
                
                index++
                //为了给撰写按钮留位置
                if index == 2 {
                    index++
                }
            }
        }
        //设置撰写按钮的 frame
        composeButton.center.x = self.frame.width * 0.5
        composeButton.center.y = self.frame.height * 0.5
        
    }
    
    //MARK: 懒加载控件
    //撰写按钮
    private lazy var composeButton:UIButton = {
        let button = UIButton()
        //点击事件
        button.addTarget(self, action: "buttonClick", forControlEvents: UIControlEvents.TouchUpOutside)
        // 设置背景图片
        button.setBackgroundImage(UIImage(named: "tabbar_compose_button_highlighted"), forState: UIControlState.Highlighted)
        button.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: UIControlState.Normal)
        // 设置图片
        button.setImage(UIImage(named: "tabbar_compose_icon_add_highlighted"), forState: UIControlState.Highlighted)
        button.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: UIControlState.Normal)
        //自动适应
        button.sizeToFit()
        return button
        
    }()
}
